The present invention relates generally to a semiconductor package, and more particularly to a semiconductor package which is realized using the warpage of a semiconductor chip.
In general, a semiconductor chip in a semiconductor package is adhered to the upper surface of a substrate, which is electrically connected to the semiconductor chip by wires, and the upper surface of the substrate is sealed to cover the semiconductor chip and the wires.
In keeping with the modern semiconductor products requiring increasingly large capacity, a semiconductor chip with a larger capacity needs to be mounted in a semiconductor package. However, there limitations to increasing the capacity of a semiconductor chip itself. To achieve the desired large capacity, a stack type semiconductor package includes two or stacked semiconductor chips packaged therein.
Making the semiconductor chips thin helps to realize the high degree of integration of semiconductor packages; however, the semiconductor chips made thin tend to warp resembling a smile-shape, in which the edge portions of the semiconductor chip, for example, in a face-up structure with an active surface facing upward, warp upward.
When a semiconductor chip is warped with the edge portions bent upward, the warpage prevents the entire surface of the semiconductor chip from being attached to a substrate, and, when the chip surface is not securely attached to the substrate, it will cause difficulties in the subsequent wire bonding process. It may be impossible not only to stack semiconductor chips but also to perform a wire bonding process due to the warped semiconductor chips.